It is known that thermoplastic polymers can be loaded with inert fillers, cast into films, and thereafter stretched to form oriented thermoplastic films. This statement is generally true, however, it must be realized that the particular components employed and the specific process parameters employed, particularly when control is difficult, can result in significantly different end products or significantly contribute to the success or failure of obtaining a desired result. For example, U.S. Pat. No. 4,118,438 teaches the use of some materials similar to those contemplated by the present invention, however, the object of the patentees is diameterically opposed to the object of the present invention. This reference is concerned with a transparent polypropylene film containing fine particles of an incompatible polymer dispersed therein. This film manifests bumps or surface projections caused by the dispersed particles and the patentees maintain that this gives the transparent film, non-blocking characteristics. In U.S. Pat. Nos. 3,697,367 and 3,795,720, there is disclosed a process for preparing an uniaxially oriented mixed polymer system. The resulting material has utility as a paper substitute and can be formed into fibers for making sheet paper.
It is an object of the present invention to present a film structure having a lustrous satin appearance of high opacity.
It is another object of this invention to present a film structure having a low water vapor transmission rate.
It is yet another object of the invention to present a process for preparing such a film structure.